Recall how you embed a youtube video in your wiki page and you play the video and at the end there are a number of suggestions of other videos you may like. Some of them may not be some becoming for your viewers. This is where safeshare.tv comes to help. Not only does SafeShare.TV remove distracting and offensive elements around YouTube videos, but it also allows you to crop videos before sharing them.

Paper Rater is free, no strings attached, and seems to perform all the same functions if not more. Additionally, it offers instruction in some areas that might be weak, such as vocabulary. http://www.paperrater.com/

Capture screenshot, annotate, edit. Save, mail, upload or share. All online. Pixtick gives you the power to capture screenshot, annotating or editing images and publishing them from within your browser. You doesn't need to download or install anything. Just launch it and you are ready.